textproduct: Rapid City

KEY MESSAGES

- Passing showers with thunderstorm chances track into the area from the south tonight.

- A cold front tomorrow will swing winds to the northwest and drag cooler air into NE WY and W SD. A few severe storms are possible across portions of south central SD.

- Another round of rain, snow in Black Hills, is likely late Sunday into Monday.

- Much colder to start the week but warmer temps return by late week.

DISCUSSION

(Tonight Through Saturday) Issued at 1045 PM MDT Sat May 16 2026

Showers are currently moving northeastward across western SD. A few of the stronger cells may produce lightning, gusty winds (30-40 mph), and some small hail but not anticipating any severe weather with these storms and overall severe threat overnight remains near zero.

Potent cold front will push through the region Sunday morning and bring another round of showers and storms to the area. As of now, buoyancy looks pretty weak (MUCAPE will be below 1000 J/kg for much of the area), though 0-6km shear values of 50-60KT could support a low end severe threat across south central SD where the front will come through in the late morning into the afternoon. Main concerns with any severe storms will be damaging wind gusts and large hail with the risk extending through the afternoon and evening hours tomorrow.

A push of gusty northwest winds may accompany the front as it crosses the region with our usual windy spots across the Sturgis and Rapid City foothills and adjacent plains and far southwestern SD seeing a brief period of low end advisory level gusts (45-50 mph). Given the low end nature of the event and the short duration, opting to not hoist any wind headlines at this time. Winds will diminish through the afternoon hours as the front exits the region.

Upper trof will push through the region Monday, bringing another round of precip to the area. Temps across the lower elevations of the South Dakota plains will remain warm enough that precip will fall as rain (though a few snow flakes may mix in as colder air aloft comes in). Temps over the Black Hills and northeastern WY, however, will be cold enough for snow and some light accumulations. Snow totals over the Black Hills have trended downward in recent model runs with it looking like snow will fall mainly during the daytime Monday. Given the time of year and the timing of the snowfall, much of the snow may melt as it hits the ground. Still, the higher elevations of the Northern Black Hills could see slushy accumulations of 3 to 5 inches.

Temperatures Sunday night through Tuesday will dip well below normal for mid-to-late May. Overnight lows will dip into the 20s to 30s Sunday night through Tuesday night. Monday's temps could very well stay steady or decrease through the day as the cooler air moves in. But the colder temps won't last long as highs in the 50s are likely Tuesday with a warming trend expected for the rest of the week.

AVIATION

(For the 18Z TAFS Through 18Z Monday) Issued At 1150 AM MDT Sun May 17 2026

Showers and storms are ongoing over central and south central SD, including PHP and ICR. Low VFR to MVFR/IFR conditions have overspread much of the region this morning. A cold front is pushing through, shifting winds out of the NW with gusts 25 to 35 knots. Showers and thunderstorm chances persist through the afternoon along the front, best chance for strong to severe storms across south- central SD. Slow improvement to VFR is expected across NE WY and western SD after 19z as the front pushes eastward.

Another round of rain/snow develops during the latter half of the forecast period (after 18/07-09z) with widespread MVFR/IFR conditions moving in overnight.

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...None.